In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 247.2 million years ago until 242 million years ago. The Anisian Age succeeds the Olenekian Age and precedes the Ladinian Age.
The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 242 Ma and ~237 Ma. The Ladinian was preceded by the Anisian and succeeded by the Carnian.
Pachypleurosauria is an extinct clade of primitive sauropterygian reptiles from the Triassic period. Pachypleurosaurs vaguely resembled aquatic lizards, with elongate forms ranging in size from 0.2–1 metre (0.66–3.28 ft), with small heads, long necks, paddle-like limbs, and long, deep tails. The limb girdles are greatly reduced, so it is unlikely these animals could move about on land. The widely spaced peg-like teeth project at the front of the jaws, indicating that these animals fed on fish. In the species Prosantosaurus, it was observed that they fed on small fishes and crustaceans which they devoured entirely and that its teeth regrew after they broke off. This was the first observation of tooth replacement in a European pachypleurosaur, with the only other discovery of such an event having been made in China.
Monte San Giorgio is a Swiss mountain and UNESCO World Heritage Site near the border between Switzerland and Italy. It is part of the Lugano Prealps, overlooking Lake Lugano in the Swiss Canton of Ticino.
Ticinepomis is an extinct genus of coelacanth lobe-finned fish which lived during the Middle Triassic period in what is now Switzerland. It contains two species, T. peyeri and T. ducanensis.
Besanosaurus is a extinct genus of Middle Triassic ichthyosaur from Monte San Giorgio of Italy and Switzerland, containing the single species B. leptorhynchus. Besanosaurus was named by Cristiano Dal Sasso and Giovanni Pinna in 1996, based on the nearly complete flattened skeleton BES SC 999, the holotype specimen. This skeleton is preserved across multiple thin rock slabs spanning 3.5 by 4 metres when assembled and took thousands of hours to prepare. Additional specimens from Monte San Giorgio that have previously been considered separate genera, including a partial skull named Mikadocephalus and a well-preserved, largely complete skeleton, have been reinterpreted as additional specimens of Besanosaurus. Putative specimens of Besanosaurus have been discovered in the Norwegian archipelago of Svalbard and Germany, although their attribution to this genus remains disputed.
Serpianosaurus is an extinct genus of pachypleurosaurs known from the Middle Triassic deposits of Switzerland and Germany. It was a small reptile, with the type specimen of S. mirigiolensis measuring 75 cm (2.46 ft) long.
Luganoia is an extinct genus of prehistoric bony fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch. Fossils were recovered from the Besano Formation of Monte San Giorgio and Besano area and from the Zhuganpo Member of Guizhou, South China. It was also reported from the Ladinian of Spain.
Besania is an extinct genus of prehistoric marine ray-finned fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern/southeastern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio area and the Prosanto Formation of canton Graubünden, Switzerland.
Colobodus is an extinct genus of marine Triassic ray-finned fish of the family Colobodontidae and order Perleidiformes. Fossils have been found in Europe and China, encompassing the former Tethys Ocean. It could reach body lengths of about 70 cm.
Dipteronotus is an extinct genus of marine stem-neopterygian ray-finned fish that existed during the Middle and Late Triassic epochs in what is now Europe and possibly Morocco. As a typical feature, it had several ridge scales in front of its dorsal fin that created a spine-like structure.
Meridensia is an extinct genus of prehistoric ray-finned fish that lived during the Anisian and Ladinian ages of the Middle Triassic epoch in what is now southern Switzerland and northern Italy. Fossils were recovered from the Besano Formation of Monte San Giorgio and Besano area at the Swiss-Italian boundary.
Wimanius is a genus of ichthyosaur from the Middle Triassic of Switzerland, containing a single species, Wimanius odontopalatus. It was described by Michael Maisch and Andreas Matzke in 1998 based on an incomplete skull from Monte San Giorgio, a mountain on the Swiss-Italian border. Wimanius possesses teeth on its palate, though whether they were located on the palatine or pterygoid is disputed. Other features of Wimanius include a large orbit and jugals with two rami of similar lengths. Different phylogenetic placements of Wimanius have been recovered by different studies, including it being a mixosaurid relative or a merriamosaur, and a monotypic family, Wimaniidae has been named for it. However, its validity has also been questioned, and synonymy with various other genera has been proposed. The only specimen of Wimanius come from the Besano Formation. During the Anisian, this region was a lagoon populated by a wide variety of marine life, including a variety of other ichthyosaurs.
Dianopachysaurus is an extinct genus of pachypleurosaur known from the lower Middle Triassic of Yunnan Province, southwestern China. It was found in the Middle Triassic Lagerstätte of the Guanling Formation. It was first named by Jun Liu, Olivier Rieppel, Da-Yong Jiang, Jonathan C. Aitchison, Ryosuke Motani, Qi-Yue Zhang, Chang-Yong Zhou and Yuan-Yuan Sun in 2011 and the type species is Dianopachysaurus dingi, thanking a Professor Ding for his help.
Eusaurosphargis is an extinct genus of a diapsid reptile, known from the Middle Triassic Besano Formation of northern Italy and Prosanto Formation of south-eastern Switzerland. It contains a single species, Eusaurosphargis dalsassoi. It was a small reptile, measuring 20 cm (7.9 in) long.
Helveticosauridae is an extinct family of basal marine reptiles known from the Middle Triassic of southern Switzerland and northern Italy.
Pectodens is an extinct genus of archosauromorph reptile which lived during the Middle Triassic in China. The type and only species of the genus is P. zhenyuensis, named by Chun Li and colleagues in 2017. It was a member of the Archosauromorpha, specifically part of the unnatural grouping Protorosauria. However, an unusual combination of traits similar and dissimilar to other protorosaurs initially led to confusion over its evolutionary relationships. In 2021, it was placed in a newly-established group, Dinocephalosauridae, along with its closest relative Dinocephalosaurus.
The Besano Formation is a geological formation in the southern Alps of northwestern Italy and southern Switzerland. This formation, a thin but fossiliferous succession of dolomite and black shale, is famous for its preservation of Middle Triassic (Anisian–Ladinian) marine life including fish and aquatic reptiles. It is exposed in the Monte San Giorgio and Besano area. It is among the formations responsible for the area being designated as a UNESCO World Heritage Site. In Switzerland, it is also known as the Grenzbitumenzone. The Anisian-Ladinian boundary lies in the upper part of the Besano Formation.
The San Salvatore Dolomite, sometimes known as the Salvatore Dolomite or San Salvatore Formation, is a Middle Triassic geological formation in Switzerland and Italy. The primarily lithology is micritic dolomite with a high proportion of algal mounds (stromatolites). It corresponds to a thick warm-water carbonate platform on the northern edge of an island in what is now the Po Plain. This formation and its local equivalents are common in the hills around Lake Maggiore, Varese, and Lugano, preserving fossils of marine invertebrates such as ammonoids, gastropods, and bivalves. At its southernmost extent on Monte San Giorgio, only the lower part of the San Salvatore Dolomite is preserved. The middle and upper parts are replaced by the Besano Formation, San Giorgio Dolomite, and Meride Limestone, which were deposited in a deeper and more anoxic basin between carbonate platforms.
Dianmeisaurus is an extinct genus of pachypleurosaur from the Middle Triassic Guanling Formation in China. The type species is D. gracilis. An additional species, D. mutaensis, was named in 2024 based on a small skeleton likely belonging to an immature individual.
